New study reveals major differences in how bisphenols accumulate in human organs

Bisphenols are a group of chemicals used in polycarbonate plastics and epoxy resins, including in some food contact applications. For a long time, bisphenol A (BPA, CAS 80-05-7) was the most widely used bisphenol, but it has become increasingly restricted due to its endocrine-disrupting properties. As awareness of BPA-related health concerns has grown, industry has replaced it with structurally similar alternatives. However, toxicity assessments have shown that these analogs are mostly just as hazardous, while toxicokinetic data describing their absorption, distribution, metabolism, and excretion (ADME) remain limited.

To address this knowledge gap, Hélène Bigonne and co-authors from ETH Zürich, Switzerland, developed human physiologically based kinetic (PBK) models for BPA and six analogs. In an article published on September 25, 2025, in Environmental Science & Technology, they reported that the assessed bisphenols differ significantly in their toxicokinetics. Upon oral exposure, internal concentrations varied by orders of magnitude between compounds, organs, and age groups.

Because BPA and its analogs differ markedly in toxicokinetics and internal exposure levels, the scientists recommend a chemical‑specific risk assessment. Given the large number of plastic chemicals (> 16,000), such comprehensive exposure assessments are time- and resource-intensive. For this reason, scientists advocate shifting from a risk‑based to a hazard‑based approach to identify chemicals of concern, arguing it is more efficient, simpler, and fit-for-purpose.

BPA and PET: A distinction worth making

It is important to clarify that PET (polyethylene terephthalate) —the material widely used for water bottles, food containers, and packaging—is chemically distinct from polycarbonate and epoxy resins that contain bisphenols. PET is polymerized from ethylene glycol and terephthalic acid, not from bisphenols, and therefore does not contain BPA or other bisphenols in its polymer structure.

Regulatory authorities including the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have confirmed that PET is BPA‑free and safe for food contact applications. While trace levels of BPA have occasionally been detected in some post-consumer recycled PET streams—likely from cross‑contamination during recycling—no detectable migration of BPA from PET packaging into food or beverages occurs under normal use conditions, and any trace presence remains orders of magnitude below regulatory safety limits.

PET remains a safe, BPA‑free, and widely used packaging material, fully compliant with global food contact regulations.

Reference

Bisphenols vary in their internal exposure, study finds | Food Packaging Forum